By Mike Kneller, PhD, Packaging Technologies and Inspection
A pouch seal is a structural element that joins flat film material and a component designed to close a pouch airtight. Traditional test methods (e.g. peel strength or burst), can measure the joint strength of the pouch seal using destructive methods that are often unreliable. A strong seal is not necessarily an airtight one, and the flow of gas or liquid through the seal (leak) is just one type of seal defect.
Several studies indicate that many of the traditional inspection methods used for seal inspection are unreliable because they fail to recognize invisible defects and falsely reject properly sealed pouches that exhibit cosmetic irregularities. However, airborne ultrasound technology has been proven in the field with online and offline installations. It has been established as one of the most effective methods for non-destructive testing of flexible packaging seals, giving this technology great promise for current and future applications.